枯草芽孢杆菌NCD-2γ射线辐射诱变研究

目的]研究60Coγ射线对枯草芽孢杆菌NCD-2致死率和突变率的影响。方法]采用100～2000Gy不同剂量γ射线辐射诱变,通过平板对峙法和牛津杯法筛选菌株。结果]得到辐射剂量与致死率和突变率之间的关系曲线;致死率随着辐射剂量增大而升高,升高速度先快后慢,在1000Gy辐照剂量下致死率达到99.50%;突变率随着辐射剂量的增大先升高后降低,在400～700Gy时产生的突变率高,均高于15%。辐射诱变的最佳条件为500Gy,平均致死率为77.71%,突变率为26.51%。结论]为枯草芽孢杆菌60Coγ射线辐射诱变提供参考依据。

Study on γ-Ray Irradiation Mutation of Bacillus subtilis NCD-2

Objective] To study the effect of 60Co γ-rays irradiation on Botrytis cinerea biocontrol strains—Bacillus subtilis NCD-2. Method] NCD-2 cells were irradiated at different doses of γ-rays from 100 to 2 000 Gy. The strains were screened by plate confrontation method and Oxford cup diffusion. Result] The curves of the relationship of irradiation dose and mutation and lethal rate were obtained. The results showed that lethal rate increased with the increasing of irradiation dose. The lethal rate of 1 000 Gy irradiation dose reached 99.50%. The mutation rate increased below 500 Gy and decreased above 500 Gy. The highest mutation rate occurred when the irradiation dose was between 400 and 700 Gy, and the average mutation rate was above 15%. The optimal irradiation dose was 500 Gy, when the average mutation rate was 26.51% and lethal rate was 77.71%. Conclusion] This study provided references for γ-rays irradiation mutation of Bacillus subtilis.